Conventional laundering techniques for the cleaning and treatment of fabric articles such as garments have long involved both traditional aqueous based washing and a technique commonly referred to as “dry cleaning”. Traditional aqueous based washing techniques have involved immersion of the fabric articles in a solution of water and detergent or soap products followed by rinsing and drying. However, such conventional immersion cleaning techniques have proven unsatisfactory on a wide range fabric articles that require special handling and/or cleaning methods due to a fabric content, construction, etceteras, that is unsuitable for immersion in water.
Accordingly, the use of the laundering method of “dry cleaning” has been developed. Dry cleaning typically involves the use of non-aqueous, lipophilic fluids as the solvent or solution for cleaning. In this manner, fabrics that are incompatible with water immersion may be cleaned and treated without the potential disastrous side effects water may present.
While a broad range of non-aqueous lipophilic fluids are available, many require the presence of low levels of water in the form of emulsions or microemulsions to maximize cleaning efficiency without sacrificing the “safety” accorded fabrics via dry cleaning. In addition, it is desirable to re-cycle and/or purify the non-aqueous, lipophilic fluids to reduce the much higher operating cost associated with dry cleaning as opposed to its aqueous based cousin. Re-cycling of the lipophilic fluids can pose special challenges when water, stains, and body soils are also present in the emulsion after its use. However, re-cycling presents special problems particularly when equipment space, cost, and safety issues are present. Thus, a cost-effective, efficient, and safe way to process or purify the lipophilic fluids after their use is desired, particularly when water and adjuncts such as emulsifiers are utilized.
Traditional separation techniques for dry cleaning solvent/water emulsions and/or mixtures typically involve distillation of all solvent-containing fluids, including those that do not require it. In this regard, distillation is used not only to remove impurities such as body soils from the post-use dry cleaning solvent, but is also used to separate solvent from water—a function that can be carried out in other ways. Distillation often involves high operating costs in the form of energy and equipment necessary to achieve the separation and, thus is undesirable in many instances, particularly when the equipment is within a consumer's home. Lastly, as noted, distillation is not necessary for all solvent-containing fluids arising from dry-cleaning. For example, evaporated solvent-water mixtures do not necessarily require distillation since they are substantially “impurity-free” and only require water-solvent separation operations.
Accordingly, the need remains for a cost effective, efficient, and safe method to treat lipophilic fluids post-use, particularly when water and emulsifiers are present.